The thing on the left is a snail, and it’s called abalone. Aside the fact that it’s edible, the abalone taught Angela Belcher, from MIT, how to turn carbon dioxide into rock-solid construction materials and thus sequester the gas for hundreds of thousands of years, instead of burying it underground, which is not as safe and as useful.
“We want to capture carbon dioxide and not put it underground, but turn it into something that will be stable for hundreds of thousands of years,” says Belcher, the W.M. Keck Professor of Energy.
Belcher and her collaborators, graduate students Roberto Barbero and Elizabeth Wood, started by genetically engineering ordinary baker’s yeast. The modified bacteria should capture carbon dioxide and turn it into calcium carbonates, which could be used as building materials. Two pounds of calcium carbonate can be produced for every pound of captured carbon dioxide.
The process has two steps. The first captures carbon dioxide in water, and the second combines the greenhouse gas with mineral ions to form solid calcium carbonates. This is where the genetically-modified yeast play their part. The researchers have also used computer simulations to determine which proteins can help the mineralization process.
“We’re trying to mimic natural biological processes,” says Belcher. But, “we don’t necessarily want to make the exact same structure that an abalone does.”
If the process is successfully industrialized, a potential source of mineral ions needed for the reaction could be the briny water produced as a byproduct of desalination, says Barbero.
Belcher’s method doesn’t require any cooling or heating, thus it’s energy efficient. If scaled up to industrial sizes, it could really be of great help to carbon sequestration and cheap construction materials.